The original challenger to the Internet Explorer monopoly hit version number 40 on Tuesday – here’s a look at what’s new.

Well, of course, that’s not entirely fair to the Firefox browser, which is still among the most-used in the world, but it’s also been around for what feels like a very long time. The original breaker of the Internet Explorer monopoly hit version number 40 on Tuesday – here’s a look at what’s new.

A streamlined, curved-edges interface to go with Windows 10 is present in Firefox 40, along with detailed instructions on how to switch your default browser back to Firefox. (Since Windows 10 defaults to using Microsoft’s new Edge browser.)

Websites known to serve deceptive software now trigger a big pop-up warning in Firefox 40, helping users avoid frustrating and possibly dangerous issues with bogus applications – one of several substantial safety upgrades in the new version.

Cross-origin resources – or outside plugins running on a website – can no longer trigger authentication dialogs on their own, meaning that compromised websites will have a tougher time getting malicious code onto users’ machines.

Firefox’s intriguing Hello communication feature – a kind of no-username-needed text, audio or video applet that works in the browser – got some new features as well, including the ability to tell invitees to a conversation what that conversation is going to be about.

Among several new dev features are a set of visualizations for performance improvement – pictured here is the new Waterfall view, designed to break down precisely what a browser is doing when it loads a particular website.